A team of researchers has found a specific place in the human genome that raises a person's risk of erectile dysfunction.

The discovery is a significant advancement in the understanding of the genetics underlying erectile dysfunction.

Erectile dysfunction, the inability to obtain and maintain an erection sufficient for sexual activity, is a common and costly condition of men of primarily middle and older ages. The disease is linked to many causes, such as neurological, hormonal and vascular factors.

Therapies based on these factors exist, but many men don't respond to them. Genetics also is suspected as a factor in about one-third of erectile dysfunction cases, but researchers have failed to make an association with any specific genomic locations until now.

The new study found that variations in a specific place in the genome - called a genetic locus - near the SIM1 gene are significantly associated with an increased risk of erectile dysfunction. The researchers ruled out that the risk was due to other known risk factors for erectile dysfunction, such as body mass index, or differences in how men describe their erectile dysfunction.

The researchers conducted a genome-wide association study in two large and diverse cohorts to investigate genetic contributors to the risk of erectile dysfunction.

The study found that variations in the SIM1 locus were associated with a 26 per cent increased the risk of erectile dysfunction. This risk was independent of known erectile dysfunction risk factors. The association was replicated in the U.K. Biobank sample, providing strong confirmation of the findings.

Erectile dysfunction has been difficult to study in part because of the differences in how patients report their symptoms. To overcome this challenge, the study looked to see whether the SIM1 locus was a risk factor when considering differences in how men reported their erectile dysfunction to their doctors.

The study then identified a biological role for this location in erectile dysfunctionsusceptibility. The SIM1 gene is known to be part of a signaling pathway that plays a central role in body weight regulation and sexual function.

Lead author Jorgenson said, "The different bits of evidence that we present in this study fit together like puzzle pieces to create a picture of how the SIM1 locus can control erectile function."

The study highlighted the potential of SIM1 as a target for the development of new treatments for erectile dysfunction, which are needed because about half of all men who try currently available pharmaceutical treatments for erectile dysfunction don't respond to them. The full findings appeared in the journal- Proceedings of the National Academy of Sciences.